Re: Emacs-diffs Digest, Vol 94, Issue 89

[Eli Zaretskii <eliz@gnu.org>]

> From: David Kastrup <dak@gnu.org>
> Date: Fri, 24 Sep 2010 22:29:02 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Or maybe you mean that Stefan thought casting was not the best idea.
> > In that case, I'd like Stefan's opinion on this one:
> >
> >> -  int frame_lines = FRAME_LINES (frame);
> >> +  EMACS_INT frame_lines = FRAME_LINES (frame);
> >
> > I think down that lane lies madness, because we have lots of struct
> > members that are Lisp integers, and assigning the result of XINT of
> > every one of them to an EMACS_INT will significantly and unnecessarily
> > increase our stack usage (on 64-bit machines).
> 
> "Significantly"?  Reality check.

Yes, indeed.  Take a look at GC some day, it uses up tens of thousands
of recursive calls as a matter of routine.

And even without GC, there are about 30 frames on the stack any time I
debug Emacs.  If we pacify -Wconversion by using EMACS_INT for every
variable that sometimes gets assigned the result of XINT or XFASTINT,
that could be quite a lot of memory waste.